In ΔABC above, BC is produced to D, /AB/ = /AC/ and ∠BAC = 50o. Find ∠ACD
-
A.
50o -
B.
60o -
C.
65o -
D.
100o -
E.
115o
Correct Answer: Option E
Explanation
ACB = ABC [Base angles of isoceles triangle]
ACB + ABC + 50o = 180o[sum of angles in a triangle]
ACB + ABC = 180o – 50o = 130o
ACB
130o2
= 65o
ACD + ACB = 180o[sum of ∠s on a straight line]
ACD + 65o = 180o
ACD = 180o – 65o = 115o